Invertebrates
Giant Ichneumon Wasp
Megarhyssa macrurus · also called long-tailed giant ichneumon
Pressing an ovipositor longer than her own body against the bark, a female giant ichneumon wasp drills steadily through solid wood toward a hidden horntail larva she has located purely by vibration and scent, a feat of precision targeting hidden entirely from view.
Overview
The giant ichneumon wasp, Megarhyssa macrurus, is native to hardwood forest habitat across eastern and central North America. Its extraordinarily long ovipositor, precise vibration-guided hunting, and harmless nature despite an intimidating appearance make it one of the most dramatic-looking yet genuinely gentle insects found in North American forests.
An egg-laying tool mistaken for a weapon
The giant ichneumon wasp’s trailing, needle-like structure looks every bit like a stinger built for defence, but it exists solely to deliver an egg precisely to a hidden target buried inside solid wood, a specialised tool with nothing to do with attacking a threat.
Status
Not Evaluated for conservation status, found across suitable hardwood forest habitat throughout its range.
Giant Ichneumon Wasp: common questions
How does the giant ichneumon wasp find a host hidden deep inside a tree?
She detects faint vibrations and chemical cues transmitted through the wood itself, allowing her to pinpoint the exact location of a hidden horntail wood-wasp larva before drilling her ovipositor to that spot.
Can the giant ichneumon wasp sting a person?
No, despite its alarmingly long trailing structure, the giant ichneumon wasp's ovipositor is purely an egg-laying tool and cannot be used to sting a person.
Why is the giant ichneumon wasp's ovipositor so long?
It needs to drill through several centimetres of solid wood to reach a host wood-wasp larva tunnelling deep inside a tree, requiring an ovipositor that can exceed the length of her own body.
Where is the giant ichneumon wasp found?
It is native to hardwood forest habitat across eastern and central North America.